Manufacture of concrete pipes

ABSTRACT

An apparatus for the manufacture of concrete pipe, in which injurious tangential force exerted between the compacting rollers and the pipe is substantially overcome. The means for overcoming or modifying the tangential force includes motor means operatively connected to drive the compacting rollers and motor means operatively and controllably connected to drive the roller head.

rated States atent n11 3,6 2,27

[72] Inventors Clifford Aubrey Baker [51] int. Cl B28b 21/24 4 Solway Drive, Glen Waverley, Victoria; [50] Field of Search /30 C, Morris Charles Kiefel, l9 Longbourne R, 30 M, 36, 126; 164/ l 14, 286; 264/269, 312 Ave., N. Clayton, Victoria, both of Australia 5 References Cited [2] Appl. No. 807,210 UNITED STATES PATENTS I 1 Filed 14,1969 3,096,556 7/1963 Woods 25/36 I 1 t n 4, 1972 2,751,657 6/1956 HOlStOn 25/36 I 1 Prwmy J 27, 1965 3,373,466 3/1968 Pausch 25/30 [33] Australia [3 l 1 61,968/ Primary Examiner-Robert D. Baldwin Continuatiomimpan of appfimfiou Ser. Assistant Examiner-DeWalden W. Jones 567,272, July 22, 1966, no b d Attorney-Stevens, Davis Miller & Mosher This application Mar. 14, 1969, Ser. No. 807210 ABSTRACT: An apparatus for the manufacture of concrete pipe, in which injurious tangential force exerted between the [54] MANUFACTURE OF CONCRETE PIPES compacting rollers and the pipe is substantially overcome. The

5 Chims, 14 Drawing s means for overcoming or modifying the tangential force includes motor means operatively connected to drive the com- [52] US. Cl 425/365, pacting rollers and motor means operatively and controllably 264/312 425/367 connected to drive the roller head.

PATENTEB .III 4 H?! SHEET 6 OF 6 MANUFACTURE OF CONCRETE PIPES This application is a continuation-inpart of my earlier copending application, Ser. No. 567,272 of July 22, 1966 (now abandoned).

The present invention relates to apparatus for the manufacture of pipes of reinforced concrete or the like and more particularly to the type of machine wherein a hollow cylindrical mould is placed with its axis vertical and concentric with the axis of a packer or roller head on which a plurality of compacting rollers are mounted with their axes parallel with the axis of the mould and their peripheries tangential to the bore of the mould, the roller head being raised slowly as it is revolved, so distributing and compacting concrete fed in from above. Generally a cylindrical reinforcement cage of welded wire mesh or the like is positioned in the mould prior to the commencement of the filling operation so that it will be embedded within the wall of the concrete pipe.

It is customary in such machines to allow the rollers to idle and thus to be made to revolve by the concrete of the pipe being compacted, a tangential component of force acting between the rollers and the concrete as the roller head carries the rollers around. This tangential force is in such a direction as to retard the motion of the roller head and conversely to drag the concrete circumferentially around the mould so that the disadvantage arises that the reinforcement cage within the concrete may be twisted or damaged and the pipe rendered unfit for further processing or for use.

If for example the power required to drive the roller head of a machine when forming a pipe 48 inches in diameter is 50 1-H. and the peripheral speed of the roller head with idling rollers is 1,000 ft. per minute the total tangential force on the rollers is 50 63,000/ 1,000 =1=,650 pounds force.

It is evident that if the rollers are independently driven, either by a motor or motors integral with the roller head there will be no tangential force on the rollers if the roller head is free to idle or if it is driven at the same peripheral speed at the pipe diameter as the rollers. Similarly, if the rollers are driven by a motor means external to the roller head through gearing within the roller head arranged so that the rotational speed and direction of the input shaft is the same as that of the rollers then it is evident that the input torque will be equal and opposite to the torque of rolling friction being overcome by the rollers and no tangential force will be applied to the pipe wall by the rollers.

It is found that for best results in terms of a minimized tangential concrete movement and damage or movement of the reinforcement cage it is advantageous to control the tangential force between concrete and rollers by the provision of an independent driving means for the rollers and by the provision of a controlled drive to the roller head. The roller head drive also may serve to start the rotation of the roller head before concrete filling commences and if desired to revolve the roller head during a finishing operation.

The present invention has for its primary object to provide the means whereby the above described tangential force may be eliminated, minimized, or controlled at will so that the disadvantage described may be considerably reduced or eliminated.

IN THE DRAWINGS FIG. 1 is an elevational view of a first embodiment of a roller head pipemaking machine according to the present invention.

FIG. 2 is a sectional plan view along line 11-11 of the machine of FIG. 1.

FIG. 3 is a plan view of a roller head for the machine of FIG. 1.

FIG. 4 is a part sectional elevation of a roller head for the machine of FIG. 1.

FIG. 5 is a plan view of an alternative roller head for a second embodiment machine according to the present invention.

FIG. 6 is a partsectional elevation of the alternative roller head for the second embodiment machine.

FIG. 7 is a pneumatic circuit diagram for control of the second embodiment machine.

FIG. 8 is an electrical circuit diagram for control of the roller head drive motor.

FIG. 9 is an hydraulic circuit diagram for the roller head vertical travel motion.

FIG. 10 is an elevational view of a third embodiment machine according to the present invention.

FIG. 11 is a sectional plan view of the machine of FIG. 10.

FIG. 12 is a plan view of the roller head of the third embodiment machine.

FIG. 13 is a part sectional elevation of the roller head of the third embodiment machine.

FIG. 14 is a circuit diagram of an alternative roller head drivemotor system.

Referring to the drawings and to the numerals of reference thereon the first embodiment machine illustrated consists of portal frame 1 with fixed crossrail 2 and fixed guide rods 4. Crosshead 3 slides vertically on guide rods 4 being lifted by chains 8 which pass around fixed deflecting sprockets 9 and travelling sprockets 7 to anchors 10. The travelling sprockets 7 are trunnion mounted on the ends of the piston rods 6 which slide in cylinders 5 which are bracketted to the portal frame 1.

In the first embodiment machine roller head 60 is fixedly attached to tubular shaft 13 which is rotatably mounted in bearing 14 and a second bearing 16 carried in housing 15 mounted on the lower end of nonrotating tubular housing 12 which is flanged mounted to the underside of moving Crosshead 3 and guided by rollers 11 carried by crossrail 2. Roller head 60 is revolved by motor 20 through pulleys 17 and 19 and belt 18 which drive the upper end of shaft 13, the motor 20 being connected to its power supply via cable 98. In the roller head 60 rollers 61 with integral packer vanes are secured by nuts 62 and keys to shafts 63 which are carried by bearings 64 in housings 66, gears 74 being keyed to the lower end of shafts 63. A small adjustment to the radial position of the rollers in the roller head is given by rotation of housings 66 about the axes of shafts 67 to which they are fixedly secured, shafts 67 pivoting in roller head 60 and cover 65. Arms 68 are welded to shafts 67 and are adjustably secured between setscrews 69 carried in lugs integral with cover 65 and locked by nuts 70.

Roller drive shaft 25 rotatably mounted inside tubular shaft 13 is driven by motor 24 via pulleys 21 and 23 and belt 22 and has splined to its lower extremity a sun gear 72 which being of the same diameter as gears 74 drives the rollers in the same speed and direction as itself through idler gears 73 which idle on bearings 71 about shafts 67. Motor 24 may be of any construction having a constant speed characteristic when set to the required speed of operation and is fed through flexible connection 97.

Mould 52 with mould ends 51 and 53 is supported on base 56. Mould 52 contains a reinforcement cage 54 and concrete 55 to form a reinforced concrete pipe.

Referring to FIG. 9 cylinders 5 are supplied from hydraulic power pack 91 through manually operated threeposition reversing valve 92 and pressurecompensated flow control valves 93 and 94 bridged by reverse flow check valves 95 and 96 and thus by operation of the reversing valve 92 they cylinders 5 may be set to raise or to lower the roller head at speeds set at the flow control valves or to hold it stationary in height.

Motor 20 is of DC shunt field construction with integral tackogenerator 46 and referring to FIG. 8 rectifier set 43 gives field supply and reversible thyristor AC DC converter set 42 gives armature supply through DC current transformer or ammeter shunt 45. Voltage regulated DC rectifier set 44 supplies current control amplifier 47, current reference potentiometer 49, speed control amplifier 48 and speed reference potentiometer 50. In operation of the machine, speed control 0 potentiometer 5! is set so that feed back from tachogenerator 46 causes the peripheral speed of rotation of the roller head 60 to be slightly less than the loaded peripheral speed of rotation of the rollers 61 so that when the driven rollers pressing on the concrete pipe wall cause the roller head to revolve at a speed slightly in excess of the preset speed given by potentiometer 50 the diode 122 cuts off a speed reducing signal and the motor armature current and hence the drive torque output from the motor will be according to the valve preset at potentiometer 49 and thus the tangential force between the rollers and the concrete may be preset to the optimum in direction and magnitude found by experiment and indicated on ammeter 121.

FIG. 14 shows a simpler and cheaper though less perfect system for the control of the output torque of motor 20. In this scheme motor 20 is a slipring AC induction motor and the rotor current and hence the output torque are controlled by variation of resistors 124 in the rotor circuit the torque being indicated by ammeter 123.

it will be appreciated that alternatively to driving the roller head by motor 20 this motor and the associated pulleys 17 and 19 may be eliminated and then with the roller drive as described for the above machine the machine will operate with zero resultant tangential force between the rollers and the pipe.

It will further be appreciated that with motor 20 eliminated it is possible to give a biasing resultant tangential force between the rollers and the pipe in either direction by making the ratio of the drive between the vertical shaft and the rollers 61 slightly above or below unity ratio but the tangential biasing force so obtained will be less controllable than may be obtained by making the roller drive ratio unity and introducing a controlled torque to the roller head from motor means. Thus referring to FIGS. 3 and 4 if the sun gear 73 is made effectively equal to half the effective diameter of the gears 74 then the driving torque to gear 73 from shaft 25 will be twice the sum of the torques reacted back from the roller gears 74 and the unbalanced torque will produce a tangential resultant between the rollers and the pipe in such a direction as would tend to drag the concrete in a direction opposite to the direction of translation of the rollers around the pipe.

It will further be appreciated that it is possible alternatively to obtain a controlled tangential bias force between the rollers and the pipe by controlling the power to the roller motor 24 and taking the measure of the power to the roller head motor 20 as a parameter of the bias force but in general it is more economical to control the power to motor 20 as it is found that the optimum operating condition calls of more power in motor 24 than in motor 20.

In the second embodiment machine of FIGS. 5 and 6 roller head 60 in the first embodiment machine is replaced by a modified roller head 80 in which the compacting rollers 61 are secured to shafts 81 carried in bearings 82 and 83 mounted in eccentric sleeves 84 with integral operating arms. Spring return air cylinders are trunnion mounted to lugs 36 fixed to the rollers head and clevises 37 on the ends of the air cylinder piston rods connect to the operating arms of eccentrics 84. Cylinders 35 are fed via hoses 34, rotary union 33, hollow shaft 30, rotary union 31 and flexible hose 32, rotary union 31 being arrested by arm 26 fixed to the moving crosshead 3.

Referring to FIG. 7 air supply to the cylinders 35 is controlled by manual two position valve 38 and pressure reducing valve 40 passing through air filter 41 and air lubricator 39 from the supply main. Thus by operation of valve 38 the rollers 61 may be retracted to inner positions where they project only slightly from the roller head or alternatively they may be caused to expand outwards by a small amount under a pressure controlled by the reducing valve 40 and so in an additional pass of the roller head through the formed pipe with the rollers expanded the pipe may be recompacted to a definite rolling pressure.

The second embodiment machine drive to the roller head from motor 20 is as described for the first embodiment machine and drive to the rollers from motor 24 is effected via pulleys 21 and 23 and belt 22, pulley 23 being keyed to hollow shaft 30. Hollow shaft 30 at its lower end is splined to sprockets 86 which are connected to the roller sprockets 85 by chains 87 the slack chain tension being maintained by springloaded takeup sprockets 88. Sprockets and 86 are of equal diameters and thus the total torque transmitted to the rollers by shaft 30 is equal to the sum of the roller frictional torques.

For the second embodiment machine the consideration of motor characteristics and control are as for the first embodiment machine.

In a third embodiment machine referring to FIGS. l0, ll, 12 and 13 a portal frame 1 carries fixed rails 2 and guide rods 4. Moving crosshead 3 slides on guide rods 4 and is lifted by yoke 112 to which it is attached, yoke 112 being lifted by wire rope 110 which passes over fixed deflecting sheaves 111 to motorised winch 109.

Roller head is carried on shaft 13 and driven by motor 20 as described for the first embodiment machine. Mould 51, 53 to contain reinforcement cage 54 and concrete 55 is carried on turntable 57. [n the roller head 100 rollers 61 are each directly mounted on the output shafts of geared motors 102 which are fed through cables 103 from junction box 104 which is fed through cable 105 which passes up the tubular shaft 13 to slip rings 106 carried on the upper end of shaft 13 below pulley 19. Slip rings 106 are fed by brushes 107 and flexible cable 108. Motors 102 may be of any type having constant speed characteristics such as AC squirrel cage induction motors or DC compound wound motors.

The consideration of the characteristic and control of motor 20 is as for the first embodiment machine.

While there has been described what are at present considered three preferred embodiments of the present invention it will be appreciated by those skilled in the art that various changes and modifications can be made therein without departing from the essence of the invention and it is intended to cover herein all such changes as come within the true spirit and scope of the appended claims.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is:

1. Apparatus for the manufacture of a reinforced concrete pipe, comprising a nonrotatable mould for receiving a concrete mixture and a reinforcement cage to form the pipe, means for compacting the concrete mixture as the pipe is formed in the mould and comprising a rotatable head supported for rotation in the mould on a center located on the axis of the mould, a first motor means for rotating the rotatable head, means for reciprocating the rotatable head longitudinally of the mould, a plurality of rotatable rollers mounted on the rotatable head for rotation on axes parallel to the axis of the mould as the rotatable head rotates to engage the inner surface of the pipe and compact the concrete mixture as the pipe is formed, a second motor means operatively connected to the rotatable rollers for rotating the rollers, and means for controlling the power output of one of the motors so that it will develop a rotary force counter to and substantially equal to the retarding tangential force exerted between the rollers and the pipe as the pipe is being formed in the mould and compacted by the rollers.

2. Apparatus according to claim 1, wherein the control means is connected to control the first motor means.

3. Apparatus according to claim 1, wherein the control means is connected to control the second motor means.

4. Apparatus for the manufacture of a reinforced concrete pipe comprising a nonrotatable vertically mounted mould for receiving a concrete mixture and a reinforcement cage, a rotatable head supported for rotation on a center located on the axis of the mould, means for moving the rotatable head axially'within the mould, a plurality of rotatable rollers mounted on the rotatable head for rotation on axes parallel to the axis of the mould to engage the inner surface of the pipe and compact the concrete mixture as the pipe is formed, driving means for rotating the rollers at a speed such that a predetermined resultant tangential force will be exerted between the rollers and the pipe as the pipe is formed in the mould and compacted by the rollers and means for operatively connecting the driving means to the rotatable rollers.

5. Apparatus according to claim 4, wherein the means for operatively connecting the motor means to the rotatable means is such that the rollers will be rotated at a speed such that substantially no resultant tangential force will be exerted between the rollers and the pipe. 5 

1. Apparatus for the manufacture of a reinforced concrete pipe, comprising a nonrotatable mould for receiving a concrete mixture and a reinforcement cage to form the pipe, means for compacting the concrete mixture as the pipe is formed in the mould and comprising a rotatable head supported for rotation in the mould on a center located on the axis of the mould, a first motor means for rotating the rotatable head, means for reciprocating the rotatable head longitudinally of the mould, a plurality of rotatable rollers mounted on the rotatable head for rotation on axes parallel to the axis of the mould as the rotaTable head rotates to engage the inner surface of the pipe and compact the concrete mixture as the pipe is formed, a second motor means operatively connected to the rotatable rollers for rotating the rollers, and means for controlling the power output of one of the motors so that it will develop a rotary force counter to and substantially equal to the retarding tangential force exerted between the rollers and the pipe as the pipe is being formed in the mould and compacted by the rollers.
 2. Apparatus according to claim 1, wherein the control means is connected to control the first motor means.
 3. Apparatus according to claim 1, wherein the control means is connected to control the second motor means.
 4. Apparatus for the manufacture of a reinforced concrete pipe comprising a nonrotatable vertically mounted mould for receiving a concrete mixture and a reinforcement cage, a rotatable head supported for rotation on a center located on the axis of the mould, means for moving the rotatable head axially within the mould, a plurality of rotatable rollers mounted on the rotatable head for rotation on axes parallel to the axis of the mould to engage the inner surface of the pipe and compact the concrete mixture as the pipe is formed, driving means for rotating the rollers at a speed such that a predetermined resultant tangential force will be exerted between the rollers and the pipe as the pipe is formed in the mould and compacted by the rollers and means for operatively connecting the driving means to the rotatable rollers.
 5. Apparatus according to claim 4, wherein the means for operatively connecting the motor means to the rotatable means is such that the rollers will be rotated at a speed such that substantially no resultant tangential force will be exerted between the rollers and the pipe. 